Thorne: Sleepyhead

Two women have been murdered simultaneously near St. Pancras station, but in different ways. When the connection is made with two other murders, months earlier but on the same day, DI Thorne realises that two serial killers are at work in a macabre partnership.

Martin Palmer, one of the killers, is caught after a failed attempt on the life of the son of one of the previous victims. He confesses to his crimes but refuses to identify his partner. Thorne decides to free him in an attempt to force the other killer to come forward.

Palmer escapes from police custody and he and his partner, Stuart Nicklin, resume their series of murders. DS Chen (Sandra Oh), desperate to prove herself, risks everything to catch the pair.